OUTLINE: This is a dose-escalation study. Patients receive recombinant fowlpox virus encoding the gp100 melanoma antigen (FPV-gp100) IV or intramuscularly to rotating sites or fowlpox virus encoding modified gp100 melanoma antigen IV every 2 weeks for 4 vaccinations. Treatment continues for a maximum of 2 courses in the absence of disease progression. Cohorts of 3-9 patients receive escalating doses of FPV-gp100 until the maximum tolerated dose (MTD) is determined. The MTD is defined as the dose preceding that at which 2 of 6 patients develop dose-limiting toxicity. Patients in 3 of 5 cohorts also receive interleukin-2 (IL-2) within 12 hours of FPV-gp100. One cohort receives IL-2 subcutaneously daily on days 1-5 and days 8-12. A second cohort receives low-dose IL-2 IV over 15 minutes every 8 hours on days 2-8. A third cohort receives high-dose IL-2 IV over 15 minutes every 8 hours on days 2-6. Patients in cohorts 4 and 5 receive FPV-gp100 alone and, if no response is observed after 2 courses, may receive 2 courses of IL-2 alone every 8 hours for 5 days, approximately 2 weeks apart. A separate cohort of 3-9 patients receives modified FPV-gp100. If no response is observed after 2 courses, IL-2 may be administered as in cohorts 4 and 5. Patients are followed at 28 days after the second immunization with FPV-gp100.